Müzik çok yüksek olunca kulaklarım ağrıyor, ben de sesi hemen kısıyorum.

Olunca comes from olmak (to be / to become / to happen) plus -ınca / -ince, a suffix that often means when, once, or sometimes since/because depending on context.

So:

• olmak → olunca
• literally: when it becomes / when it is

In this sentence, Müzik çok yüksek olunca means something like:

• when the music is very loud
• when the music gets very loud

It sets up the situation that causes the rest of the sentence.

That is just the normal Turkish way of talking about volume.

• yüksek ses = loud sound
• alçak / kısık ses = low / quiet sound

So Müzik çok yüksek literally looks like The music is very high, but the natural meaning is The music is very loud.

This is a very common vocabulary difference from English.

Kulaklarım means my ears:

• kulak = ear
• kulaklar = ears
• kulaklarım = my ears

Turkish often uses the plural for body parts that naturally come in pairs, where English might sometimes prefer singular depending on context.

So:

• kulaklarım ağrıyor = my ears hurt

This is completely natural Turkish.

It breaks down like this:

• kulak = ear
• -lar = plural
• -ım = my

So:

• kulak → ear
• kulaklar → ears
• kulaklarım → my ears

This is a very common Turkish pattern:

• kitaplarım = my books
• gözlerim = my eyes
• ellerim = my hands

Good question. In Turkish, when the subject is explicitly plural, the verb is often left in singular form, especially in everyday usage.

So both the idea and the grammar are normal in:

• Kulaklarım ağrıyor = My ears hurt

Using ağrıyorlar is generally not needed here, and ağrıyor sounds more natural.

This is common with many plural subjects in Turkish.

It can do both.

The -yor form is often called the present continuous, but in real Turkish it can also describe:

• something happening right now
• a repeated situation
• a habitual reaction

In this sentence, it most likely expresses a repeated/general situation:

• When the music is very loud, my ears hurt, so I immediately turn the volume down.

So even though the verbs are in -yor, the meaning is not limited to one exact moment.

Here ben de means something like:

• I too
• so I
• I, then
• for my part, I

In this sentence, it connects the second action to the first situation:

• kulaklarım ağrıyor, ben de sesi hemen kısıyorum
• my ears hurt, so I immediately turn the sound down

The de adds the sense of in response / as a result / too.

Because this de is the separate word meaning too / also.

So:

• ben de = I too / so I

This is different from the suffix -de meaning in / at / on:

• evde = at home
• okulda = at school

A useful rule:

• separate de = too / also
• attached -de = location (in, at, on)

Because sesi is the definite direct object form of ses (sound / volume).

• ses = sound
• sesi = the sound / the volume

Turkish usually marks a specific direct object. Here the speaker means a specific thing: the sound/the volume that is currently too loud.

So:

• sesi kısıyorum = I turn the sound/volume down

This is very natural Turkish.

Yes. Kısmak basically means to reduce / lower / cut down.

With ses, it becomes the normal expression for turning the volume down:

• sesi kısmak = to turn the sound down
• sesi açmak = to turn the sound up

So Turkish uses a verb meaning reduce where English uses the phrasal verb turn down.

Yes, you may hear that in everyday speech, and people would understand it as I turn the music down.

But sesi kısmak is especially common because what you are really lowering is the volume/sound level, not the music itself.

So:

• sesi kısmak = very standard and precise
• müziği kısmak = also understandable and used in speech

It could be left out.

Turkish often drops subject pronouns because the verb ending already shows the person:

• kısıyorum = I am turning down / I turn down

So the sentence could also be:

• Müzik çok yüksek olunca kulaklarım ağrıyor, sesi hemen kısıyorum.

Adding ben gives a little more emphasis or contrast, like:

• so I immediately turn it down

Turkish often puts the time/cause/condition part before the main action.

So the structure is:

• Müzik çok yüksek olunca = when the music is very loud
• kulaklarım ağrıyor = my ears hurt
• ben de sesi hemen kısıyorum = so I immediately turn the sound down

This order feels very natural in Turkish because it presents:

1. the situation
2. the result
3. the response

Not exactly, because the nuance changes.

• olunca = when it is / when it gets
• olursa = if it is / if it gets

So:

• Müzik çok yüksek olunca sounds like a regular, real situation: when the music gets very loud
• Müzik çok yüksek olursa sounds more conditional: if the music gets very loud

In this sentence, olunca fits better because the speaker is describing what normally happens.